Tim Cook used part of his address to graduating students at Massachusetts Institute of Technology on Friday to poke fun at President Donald Trump.

The Apple CEO began by saying he’d never figured out how students at the university in Cambridge pulled off their spectacular course-end pranks ― such as the placing of a propeller atop the campus’ Great Dome.

“Or how you’ve obviously taken over the president’s Twitter account,” Cook added. “I can tell college students are behind it because most of the tweets happen at 3 a.m.”

Tim Cook just dissed Trump's twitter activity SO HARD and I'm living for it

Cook went on to deliver some serious advice to the class of 2017, and the effect that the online world may have on their lives.

“The internet has enabled so much and empowered so many. But it can also be a place where the basic rules of decency are suspended and pettiness and negativity thrive,” Cook said.

He encouraged students not to let “the noise knock you off course” or to “get caught up on the trivial aspects of life.”

“Don’t listen to the trolls, and for God’s sake don’t become one,” Cook added. “Measure your impact on humanity not in likes, but in the lives you touch. Not in popularity, but in the people you serve.”